Scattered around Britain in secret bunkers, they were poised to strike fear into Hitler's troops had they reached the mainland.

The brave young men of the lethal Auxiliary Unit had been trained in the art of sabotage - from booby traps to 'time pencil' fuses.

Now, a collection of Second World War artefacts is up for auction which sheds light on the nation's secret last line of defence.

It includes cleverly disguised guides to bomb-making - hidden inside a calendar and fertiliser manual - which were used by the unit, adopting the status of the Home Guard as cover for their real activities.

The items for sale belonged to Louis
Pugh, a chemical factory owner-turned-guerrilla fighter charged with
heading the sabotage division of his local cell.

A collection of WWII artefacts from the deadly Auxiliary Unit wing of the Home Guard has come to light, including cleverly
disguised manuals on bomb-making and sabotage. The manuals were disguised as calendars and fertiliser guides (above)

The items for sale belonged to Louis Pugh, a chemical factory owner-turned-guerrilla fighter charged with heading the sabotage division of his local cell of the Auxiliary Unit. The resistance division was the brainchild of Winston Churchill, who ordered a network of hidden bunkers to be set up around the country in case of invasion by Hitler's troops. Above is one of Pugh's bomb fuses

The Auxiliary Unit was the brainchild
of Winston Churchill, who ordered a network of hidden bunkers to be set
up around the country in case of invasion by Hitler’s troops.

The unit’s creation came after the Allies suffered heavy losses and had to be evacuated from Dunkirk in northern France in mid-1940.

Many of the concealed bases were in East Anglia, the most probable landing point for Hitler’s planned attack Operation Sealion.

Their very existence was on a strictly need-to-know basis and they were manned by only the most trusted members of the community.

The volunteer members were trained in guerrilla warfare as assassins and saboteurs with orders to attack from behind enemy lines should the Nazis invade.

Pugh (above) was one of six men based at a hideout at Gibbet Oak Farm in Tenterden, Kent. Hidden in woodland, it boasted a hydraulic entrance that had been fitted by the local garage owner

The artefacts are tipped to fetch a total of £3,000 when they go under the hammer next week. Above, Pugh's radio set

Among Pugh's collection of mementos are manuals on how to make bombs using readily available chemicals and how to set booby traps

Members anticipated being shot if they were captured, and were expected to shoot themselves rather than be taken alive.

Thankfully, victory for the Allies in the Battle of Britain put paid to Hitler’s plans for invasion and the Auxiliary Unit were never called into action.

Amazingly, the unit’s existence only became public knowledge many years after the end of the war.